High resolution solid state nmr gives information about structure of local sites in solid state samples, and has an advantage over X-ray diffraction method at the point of reflecting difference between nucleuses with near atomic numbers. An outline of CP/MAS nmr, which is a typical high resolution solid state nmr technique, is given here. And, problems of orientational disorder of bridging cyano groups in metal cyanide complexes are introduced as an actual crystal structure study using solid state nmr and diffraction method.
Characteristic dynamical diffraction effect on electron diffraction patterns of alloys is discussed based on the multislice method. The dynamical diffraction effect on the scattering amplitude of superlattice reflections of long-range-ordered alloys and the intensity of diffuse scattering of short-range-ordered alloys are represented with the so-called “dynamical factor”. It is shown that the dynamical factor can be estimated as far as alloy composition and basic structure are known without the knowledge of specific ordered atomic arrangements. It is also found that the dynamical factor changes drastically with the increase in the crystal thickness but does not change so much with the reciprocal-lattice vector. Characteristic features of high-resolution electron microscope images and electron diffraction patterns of alloys are discussed with the dynamical factor.
It was found in some aqueopus solutions that there are typically three regions in the single phase domain of the composition-temperature field, in each of which the mixing scheme is qualitatively different from those of other regions. In the water-rich region (I), the hydrogen bond strength of solvent H2O is enhanced in the vicinity of a solute molecule, while the hydrogen bond prbability in the bulk away from a solute is reduced. The percolation nature of hydrogen bond network is still retained in this region (I) . In the intermediate region (II), the solution consists of two kinds of clusters rich in each component. Therefore the percolation nature is no longer present. In the solute rich region (III), the solute molecules cluster together and H2O molecules are “adsorbned” on the surfaces of such clusters. The transition from the water-rich (I) to the intermediate (II) region is associated with anomalies in the third derivatives of Gibbs energy.
Structure changes and dielectric properties of strained artificial superlattices of BaTiO3/SrTiO3 are discussed in this article. A large strain of 0.5-1GPa is introduced at the interface between BaTiO3 and SrTiO3 layers, and a large dielectric constant of 900 is observed with stacking periodicity of 2 unit cells/2 unit cells for the total thickness of 2000Å. The superlattices show drastically different dielectric behavior from that of the solid solution (Sr, Ba) TiO3 films. Broad maxima of the dielectric constants occur around 40-50°C and the values remain large even at a temperature above 200°C.